Horne suffered a traumatic head injury in the crash near the Channel Islands west of Malibu, Coast Guard officials said.

The second man was treated for minor injuries. His name wasn't released.

Homeland Security Secretary Janet Napolitano said Monday that Horne and fellow crewmembers of the Coast Guard cutter Halibut "were engaged in an at-sea interdiction when they came under threat by a small vessel that rammed their small boat."

A Coast Guard aircraft spotted a panga -an open, low-sided fishing boat favored by Mexican smugglers - before dawn and the cutter Halibut was sent to intercept it, officials said.

The cutter deployed a smaller inflatable chase boat but as that vessel approached the panga with its blue light flashing, the panga veered toward it at high speed and struck it before fleeing.

Horne and another crewman were thrown into the water.

Another Coast Guard vessel stopped the fleeing panga and detained two suspects.

Asked whether any drugs were found, Coast Guard spokesman Adam Eggers said he could not immediately comment.

Smuggling boats carrying drugs or illegal immigrants from Mexico have been ranging farther and farther north along the California coast.

"Our fallen shipmate stood the watch on the front lines protecting our nation, and we are all indebted to him for his service and sacrifice," said Admiral Robert J. Papp, Coast Guard Commandant.

Napolitano said the tragedy was a reminder of the dangers men and women in uniform face daily while protecting the nation. She said her thoughts and prayers were with Horne's family and all Coast Guard personnel.

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